first of all do not consider the level the student has to reach. Evaluate his / her true needs. Make a general evaluation according to the level of the exam (s)he wants to sit for. Try to have a blank �exam � and give it him / her.
Once the weaknesses identified make sure with some exercises of the real degree of the need in the point to study.
According to the implication of the student and his / her rapidity of understanding you would be able to consider how long (an average time of course) it would take to revise or study all the necessary points.
If there is a lack of vocabulary ask the student to make his / her OWN dictionary. I mean : does (s)he prefer �verbs / adjectives / common names.... � classification ? �alphabetical � classification first in English than in his / her mother tongue ? �around a root � classification ? �a theme � classification ? ....
Are these specific grammar points ? Take several colors to underline the main elements of the studied topic. Of course the colors will become a personal code for him / her. Give him / her several and detailed examples for each precise point and make him / her find his / her own.
Let him / her choose the book that appeals him / her. You work better with a book you take with pleasure.
Congratulate him / her every time (s)he has understood something, new or not.
Adapt your teaching on his / her �thirst � of learning. NEVER consider the level (s)he is supposed to have : give him / her every possible knowledge that can help him / her to improve in the most deepest way.
English is a very PRAGMATICAL, CHRONOLOGICAL and coherent language. Make him / her notice the similarities in the changing of spelling (for example : words ending with a consonnant + y see the �y � becoming �i � when there is a suffix except the suffix �-ing �.)
Find funny mnemotechnics, if possible his / hers (they may be very personal).
You may be surprise of the very good results.
Hope this could help you. Good work for both of you and do not underestimate your own value or your student �s capacity to work fast ! This is a golden rule because that way you will always suit your student �s rythm of work and you will improve your own knowledge in teaching methods when you will have to understand what the students need !